Paris Olympics organisers promised to take "unprecedented" action for the climate by halving the carbon footprint of previous Games and financing projects to reduce planet-heating greenhouse gases. But experts remain sceptical, especially after organisers dropped a pledge to set a hard limit on its overall carbon cost. About one-third of the heat-trapping emissions from the three-week spectacle is expected to come from transport, with millions of athletes, spectators, staff and journalists flying into Paris.

Efforts by Paris 2024 organisers to make this year's Olympic Games the greenest in history are being challenged by athletes who plan to bring their own air conditioning to the Olympic Village, after the announcement of a sustainability plan that does not include air conditioning in athletes' areas.